S2BAVG: A global Sentinel-2 grid for burned area product validation

Accurate burned area (BA) mapping is essential for assessing wildfire impacts on ecosystems and climate. While existing BA products derived from coarse-resolution sensors (e.g., MODIS) have primarily relied on Landsat-based validation protocols, the advent of higher-resolution products such as those from Sentinel-2 necessitates adapted validation methodologies to match their enhanced spatial detail. This study presents the Sentinel-2 Burned Area Validation Grid (S2BAVG); a global sampling framework designed to support BA validation using Sentinel-2 imagery. S2BAVG consists of 19,263 non-overlapping spatial units covering the global land surface, addressing limitations of previous grids by ensuring full orbital coverage and eliminating overlaps, thereby enabling consistent sampling and rigorous validation. Key attributes—including fire activity indicators and cloud-free image availability— facilitate the implementation of stratified sampling designs. Additionally, we provide an open-source framework to support the sampling process with customizable input parameters. The framework includes statistical inference tools to estimate accuracy metrics and their standard errors, ensuring rigorous BA product assessment. By leveraging Sentinel-2′s high spatial and temporal resolution, S2BAVG provides a flexible and standardized methodology for BA validation. The S2BAVG tile grid dataset and sampling framework (with an illustrative sampling design approach) are openly available at https://github.com/magifranquesa/S2BAVG, promoting reproducibility and enabling broader applications in fire science and Earth observation.